171results about How to "Increase the bandgap" patented technology

A system and method for lower cost, high efficiency, thermophotovoltaic distributed generation includes: an emitter, a photovoltaic cell, and transient electrical energy storage.

The present invention provides a photovoltaic cell comprising a GaInP subcell comprising a disordered group-III sublattice, a Ga(In)As subcell disposed below the GaInP subcell, and a Ge substrate disposed below the Ga(In)As subcell comprising a surface misoriented from a (100) plane by an angle from about 8 degrees to about 40 degrees toward a nearest (111) plane.

The invention discloses a transverse IV-clan element quantum well photoelectric detector and mainly solves problems of high material toxicity and high cost of a conventional infrared photoelectric detector. The transverse IV-clan element quantum well photoelectric detector comprises a substrate (1), a bottom electrode (2), an absorption region (3), and a top electrode (4). A quantum well (31) uses a GeSn strain monocrystalline material with a Sn component more than or equal to 0 but less than 0.3. A barrier layer (32) uses a monocrystalline material with a Sn component more than or equal to 0 but less than 0.3 and a Ge component more than or equal to 0 but less than 1. The quantum well (31) and the barrier layer (32) are stacked transversely to form the absorption region arranged between the bottom electrode and the top electrode. According to the invention, SiGeSn monocrystalline material changes in size in an epitaxial process so as to generate transverse tensile strain in the GeSn quantum well material, thereby changing a GeSn material band gap and enlarging the spectral response range of the detector. The SiGeSn monocrystalline material can be used for producing large-scale integrated circuit.

The invention discloses a double-side growth four-junction solar cell with a reflecting layer and a preparation method thereof, and the solar cell comprises a GaAs substrate; the GaAs substrate is an n-type GaAs single-crystal slice that is polished in two sides; a GaAs buffer layer, a first tunnel junction, a AlGaAs/GaInAs DBR reflecting layer, a GaInNAs sub-cell, a second tunnel junction, a AlAs/AlGaAs DBR reflecting layer, a GaAs sub-cell, a third tunnel junction, a GaInP sub-cell, an ohmic contact layer, an antireflection coating, and a front electrode grow on the upper surface of the GaAs substrate from top to bottom; a Ga1-zInzP strain buffer layer, a Ga1-xInxAs sub-cell and a back electrode are provided on the lower surface of the GaAs substrate in order. According to the invention, photon absorption efficiency can be raised; at the same time, the advantages of the four-junction solar cell can play their roles; the integral open-circuit voltage and a fill factor of the GaAs multi-junction cell can be raised; and the photoelectric conversion efficiency of the cell can be improved finally.

The invention provides a low-frequency, broad-band and local-area resonance structure with super damping characteristics. The structure comprises a rhombic frame; a first end of the rhombic frame is connected with a basal body beam through a rubber block; rubber bars are arranged on short diagonal lines in the rhombic frame; and one ends of the rubber bars are connected with the first end of the rhombic frame, and the other ends are connected with a second end of the rhombic frame. Mass blocks are arranged at two ends of the rhombic frame, and the structure is periodically added on a beam unit, so that the low-frequency band gap is widened, and the vibration attenuation is enhanced. The structure is better in geometric nonlinearity, can generate additional damping and mass, and effectivelyimproves low-frequency vibration characteristics of a system.

A dynamic random access memory cell that includes a transistor formed in a semiconductor body. A capacitor is coupled to the transistor and includes a first capacitor plate formed from silicon. A metal layer is adjacent to and electrically coupled to the first capacitor plate. A capacitor dielectric layer is adjacent to the metal layer. The capacitor dielectric layer comprises material having a dielectric constant greater than about 5. A second capacitor plate is adjacent to the capacitor dielectric. The capacitor can be either a trench capacitor or a stacked capacitor.

Disclosed a method for one time extension forming the semiconductor laser and mode spot switch comprises following steps: (1), on the N type indium phosphide substrate, extending growing the N type indium phosphide breaker, a lower waveguide layer, a 2.4 ª–m indium phosphide space layer, a lower light-limited layer of active region, a compression strain quanta active region, a upper light-limited layer, a P type indium phosphide envelope, and a high doping P type indium gallium arsenide ohmic electrode contract layer; (2), utilizing the wet corrosion process to etch the upper carinate shape of laser and mode spot switch; (3) utilizing the auto-alignment process to etch the lower carinate shape; (4), growing the SiO2 insulating layer and opening a electrode window; (5) decreasing the substrate of extended plate to 100 ª–m, and manufacturing P/N electrodes to be scribed into the tube core of 250í‡600ª–m.

The invention relates to a preparation method of a black phosphorus nano lamina for photocatalytic degradation of dye wastewater. The method specifically comprises the following steps: (1) preparing multilayer black phosphorus, namely grinding red phosphorus without a surface oxidation layer in a mortar, and then performing mechanical ball milling to obtain the multilayer black phosphorus; and (2) preparing the black phosphorus nano lamina, namely adding the multilayer black phosphorus and a surfactant into water together, performing primary ultrasonic treatment and primary centrifugation, then collecting supernatant, adding the supernatant into water, stirring the materials uniformly, then performing secondary ultrasonic treatment, performing secondary centrifugation to obtain a solid deposit, and drying the solid deposit to obtain the black phosphorus nano lamina. Compared with the prior art, the preparation method provided by the invention is simple in preparation process, high in preparation efficiency, and suitable for large-scale production, and the prepared black phosphorus nano lamina has a higher specific surface area and band gap and photocatalytic activity, and can be used for performing photocatalytic efficient degradation on coloring agents including methylene blue in the dye wastewater.

A laser diode includes a substrate having a lattice constant of GaAs or between GaAs and GaP, a first cladding layer of AlGaInP formed on the substrate, an active layer of GaInAsP formed on the first cladding layer, an etching stopper layer of GaInP formed on the active layer, a pair of current-blocking regions of AlGaInP formed on the etching stopper layer so as to define a strip region therebetween, an optical waveguide layer of AlGaInP formed on the pair of current-blocking regions so as to cover the etching stopper layer in the stripe region, and a second cladding layer of AlGaInP formed on the optical waveguide layer, wherein the current-blocking regions having an Al content substantially identical with an Al content of the second cladding layer.

Disclosed a method for utilizing the dual-waveguide technology to manufacture the semiconductor laser and mode spot switch comprises following steps: on the N type indium phosphide substrate, sequentially extending growing the N type indium phosphide breaker, a lower waveguide layer, a space layer, a active region, and a thinner indium phosphide intrinsic layer, wherein, the indium phosphide intrinsic layer can prevent the oxidation of active region; removing the highest indium phosphide intrinsic layer, partly covering the laser with SiO2, and utilizing the wet corrosion process to etch the upper carinate shape of mode spot switch; utilizing the auto-alignment process to etch the lower carinate shape which comprises a lower waveguide layer, a space layer, a second growth P type indium phosphide coating layer, and a high doping P type indium gallium arsenide ohmic electrode contract layer; utilizing the SiO2 to partly cover the mode spot switch and etching the upper and lower carnate shapes again while the upper carinate shape comprises a active region, a P type indium phosphide coating layer and a high doping P type indium gallium arsenide ohmic electrode contract layer; and decreasing the substrate of extended plate to 100 ª–m, and manufacturing P/N electrodes to be scribed into the tube core of 250í‡500ª–m.

A semiconductor laser device is disclosed that improves reliability during high-power oscillation. On a plane of an n-type GaAs substrate, grown are an n-type GaAs buffer layer, an n-type In0.48Ga0.52P lower cladding layer, an n-type or i-type Inx1Ga1-x1As1-y1Py1 optical waveguide layer, an i-type GaAs1-y2Py2 tensile-strain barrier layer, an Inx3Ga1-x3As1-y3Py3 compressive-strain quantum-well active layer, an i-type GaAs1-y2Py2 tensile-strain barrier layer, a p-type or i-type Inx1Ga1-x1As1-y1Py1 upper optical waveguide layer, a p-type In0.48Ga0.52P first upper cladding layer, a GaAs etching stop layer, a p-type In0.48Ga0.52P second upper cladding layer and a p-type GaAs contact layer. Two ridge trenches are formed on the resultant structure, and current non-injection regions are formed by removing the p-type GaAs contact layer in portions extending inwardly by 30 mum from cleavage positions of edge facets of the resonator on a top face of a ridge portion between the ridge trenches.

A method and a multijunction solar device having a high band gap heterojunction middle solar cell are disclosed. In one embodiment, a triple-junction solar device includes bottom, middle, and top cells. The bottom cell has a germanium (Ge) substrate and a buffer layer, wherein the buffer layer is disposed over the Ge substrate. The middle cell contains a heterojunction structure, which further includes an emitter layer and a base layer that are disposed over the bottom cell. The top cell contains an emitter layer and a base layer disposed over the middle cell.

A number of light-emitting layer structures for the GaN-based LEDs that can increase the lighting efficiency of the GaN-based LEDs on one hand and facilitate the growth of epitaxial layer with better quality on the other hand are provided. The light-emitting layer structure provided is located between the n-type GaN contact layer and the p-type GaN contact layer. Sequentially stacked on top of the n-type GaN contact layer in the following order, the light-emitting layer contains a lower barrier layer, at least one intermediate layer, and an upper barrier layer. That is, the light-emitting layer contains at least one intermediate layer interposed between the upper and lower barrier layers. When there are multiple intermediate layers inside the light-emitting layer, there is an intermediate barrier layer interposed between every two immediately adjacent intermediate layers.

A UV light emitting diode having improved internal quantum efficiency is provided. The UV light emitting diode includes: an n-type contact layer including an AlGaN layer or an AlInGaN layer; a p-type contact layer including a AlGaN layer or an AlInGaN layer; and an active layer of a multi-quantum well structure. The active area of the multi-quantum well structure includes barrier layers and well layers which are alternately stacked. The well layers include electrons and holes present according to probability distributions thereof. The barrier layers are formed of AlInGaN or AlGaN and have an Al content of 10% to 30%. At least one of the barrier layers has a smaller thickness than of the well layers and at least one of the barrier layers has a thickness and a band gap preventing electrons and holes injected into and confined in a well layer adjacent to the barrier layer from spreading into another adjacent well layer. So driving voltage of the UV light emitting diode is reduced, and the internal quantum efficiency is improved.

The invention relates to a nano silicon window layer with the gradient band gap characteristic, which is formed by depositing on the surface of a sample to be processed, wherein the surface of the sample to be processed is sequentially stacked with a metal back electrode M, a transparent conductive back electrode T1, an n-type Si-based thin film N and an intrinsic Si-based thin film I. The nano silicon window layer is formed by sequentially stacking a silicon thin film P1, a silicon thin film P2 and a silicon thin film P3. A preparation method of the nano silicon window layer comprises the following steps: depositing the p-type silicon thin film P1 with small thickness under a low glow power; then gradually raising the power and depositing the thin film P2; and finally, and completing the window layer P3 under a high power. The nano silicon window layer has the advantages that when the nano silicon window layer is applied to the window layer of an n-i-p-type silicon-based thin film solar cell, high electric conductance and wide band gap can be acquired, the bombardment of a solar cell i/p interface can be effectively reduced, the band gap matching between an intrinsic layer and the window layer can be implemented and the filling factor, the open-circuit voltage and the spectral response of the solar cell are obviously improved, so that the silicon-based thin film solar cell with high photoelectric conversion efficiency is obtained.

In a semiconductor-laser device: a compressive-strain quantum-well active layer is made of Inx3Ga1. x3As1-y3Py3 (0<x3<=0.4 and 0<=y3<=0.1); tensile-strain barrier layers made of Inx2Ga1-2AS1-y2P1-y2 (0<=x2<0.49y2 and 0<y2<=0.4)are formed above and under the compressive-strain quantum-well active layer; and optical waveguide layers being made of either p-type or i-type In0.49Ga0.51P are formed above the upper tensile-strain barrier layer and under the lower tensile-strain barrier layer. Preferably, the absolute value of a sum of a first product and a second product is less than or equal to 0.25 nm, where the first product is a product of a strain and a thickness of said compressive-strain active layer, and the second product is a product of a strain of said lower and upper tensile-strain barrier layers and a total thickness of the lower and upper tensile-strain barrier layers.

The invention discloses a periodic cavity type vibration isolator with low frequency and a broad-band gap and a preparation method. The vibration isolator comprises two or more than two periodic units. Each periodic unit comprises two thin plate main bodies and a ring cavity scattering body, wherein outer edges of the two thin plate main bodies are connected by virtue of the ring cavity scattering body to form a cavity; and the periodic units are connected through a connecting block scattering body. The preparation method comprises the following steps: selecting materials to prepare the thin plate main bodies, the ring cavity scattering body and the connecting block scattering body; regulating geometrical parameters of the thin plate main bodies, the ring cavity scattering body and the connecting block scattering body, so that effective band gap frequency of the vibration isolator can cover vibrating frequency of a required vibration isolating environment; checking whether the vibration isolator meets a safety condition or not so as to prepare the periodic cavity type vibration isolator with low frequency and the broad-band gap. The periodic cavity type vibration isolator disclosed by the invention is suitable for isolating low-frequency vibration, can realize vibration isolation within a wide frequency range while keeping corresponding bearing capacity, can form a band gap at a lower-frequency band, and has a boarder band gap, a relatively small dimension, and higher vibration attenuation rate.